package com.lambda.cloud.core.utils;

import com.lambda.cloud.core.exception.IllegalArgumentException;
import com.lambda.cloud.core.exception.IllegalStateException;
import java.util.Collection;
import java.util.Map;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;

/**
 * @author Jin
 */
public class Assert {
    private Assert() {}

    /**
     * Assert a boolean expression, throwing an {@code IllegalStateException} if
     * the expression evaluates to {@code false}.
     * <p>
     * Call {@link #isTrue} if you wish to throw an
     * {@code IllegalArgumentException} on an assertion failure.
     *
     * <pre class="code">
     * Assert.state(id == null, "The id property must not already be initialized");
     * </pre>
     *
     * @param expression
     *            a boolean expression
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalStateException
     *             if {@code expression} is {@code false}
     */
    public static void state(boolean expression, String message) {
        if (!expression) {
            throw new IllegalStateException(message);
        }
    }

    /**
     * Assert a boolean expression, throwing an {@code IllegalArgumentException}
     * if the expression evaluates to {@code false}.
     *
     * <pre class="code">
     * Assert.isTrue(i &gt; 0, "The value must be greater than zero");
     * </pre>
     *
     * @param expression
     *            a boolean expression
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if {@code expression} is {@code false}
     */
    public static void isTrue(boolean expression, String message) {
        if (!expression) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert a boolean expression, throwing an {@code IllegalArgumentException}
     * if the expression evaluates to {@code true}.
     *
     * <pre class="code">
     * Assert.isFalse(exist, "The key already exists");
     * </pre>
     *
     * @param expression
     *            a boolean expression
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if {@code expression} is {@code true}
     */
    public static void isFalse(boolean expression, String message) {
        if (expression) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that an object is {@code null}.
     *
     * <pre class="code">
     * Assert.isNull(value, "The value must be null");
     * </pre>
     *
     * @param object
     *            the object to check
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the object is not {@code null}
     */
    public static void isNull(Object object, String message) {
        if (object != null) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that an object is not {@code null}.
     *
     * <pre class="code">
     * Assert.notNull(clazz, "The class must not be null");
     * </pre>
     *
     * @param object
     *            the object to check
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the object is {@code null}
     */
    public static void notNull(Object object, String message) {
        if (object == null) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that the given String is not empty; that is, it must not be
     * {@code null} and not the empty String.
     *
     * <pre class="code">
     * Assert.hasLength(name, "Name must not be empty");
     * </pre>
     *
     * @param text
     *            the String to check
     * @param message
     *            the exception message to use if the assertion fails
     * @see StringUtils#hasLength
     * @throws IllegalArgumentException
     *             if the text is empty
     */
    public static void hasLength(String text, String message) {
        if (!StringUtils.hasLength(text)) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that the given String contains valid text content; that is, it
     * must not be {@code null} and must contain at least one non-whitespace
     * character.
     *
     * <pre class="code">
     * Assert.hasText(name, "'name' must not be empty");
     * </pre>
     *
     * @param text
     *            the String to check
     * @param message
     *            the exception message to use if the assertion fails
     * @see StringUtils#hasText
     * @throws IllegalArgumentException
     *             if the text does not contain valid text content
     */
    public static void hasText(String text, String message) {
        if (!StringUtils.hasText(text)) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that the given text does not contain the given substring.
     *
     * <pre class="code">
     * Assert.doesNotContain(name, "rod", "Name must not contain 'rod'");
     * </pre>
     *
     * @param textToSearch
     *            the text to search
     * @param substring
     *            the substring to find within the text
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the text contains the substring
     */
    public static void doesNotContain(String textToSearch, String substring, String message) {
        if (StringUtils.hasLength(textToSearch)
                && StringUtils.hasLength(substring)
                && textToSearch.contains(substring)) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that an array contains elements; that is, it must not be
     * {@code null} and must contain at least one element.
     *
     * <pre class="code">
     * Assert.notEmpty(array, "The array must contain elements");
     * </pre>
     *
     * @param array
     *            the array to check
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the object array is {@code null} or contains no elements
     */
    public static void notEmpty(Object[] array, String message) {
        if (ObjectUtils.isEmpty(array)) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that an array contains no {@code null} elements.
     * <p>
     * Note: Does not complain if the array is empty!
     *
     * <pre class="code">
     * Assert.noNullElements(array, "The array must contain non-null elements");
     * </pre>
     *
     * @param array
     *            the array to check
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the object array contains a {@code null} element
     */
    public static void noNullElements(Object[] array, String message) {
        if (array != null) {
            for (Object element : array) {
                if (element == null) {
                    throw new IllegalArgumentException(message);
                }
            }
        }
    }

    /**
     * Assert that a collection contains elements; that is, it must not be
     * {@code null} and must contain at least one element.
     *
     * <pre class="code">
     * Assert.notEmpty(collection, "Collection must contain elements");
     * </pre>
     *
     * @param collection
     *            the collection to check
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the collection is {@code null} or contains no elements
     */
    public static void notEmpty(Collection<?> collection, String message) {
        if (CollectionUtils.isEmpty(collection)) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that a Map contains entries; that is, it must not be {@code null}
     * and must contain at least one entry.
     *
     * <pre class="code">
     * Assert.notEmpty(map, "Map must contain entries");
     * </pre>
     *
     * @param map
     *            the map to check
     * @param message
     *            the exception message to use if the assertion fails
     * @throws IllegalArgumentException
     *             if the map is {@code null} or contains no entries
     */
    public static void notEmpty(Map<?, ?> map, String message) {
        if (CollectionUtils.isEmpty(map)) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that the provided object is an instance of the provided class.
     *
     * <pre class="code">
     * Assert.instanceOf(Foo.class, foo, "Foo expected");
     * </pre>
     *
     * @param type
     *            the type to check against
     * @param obj
     *            the object to check
     * @param message
     *            a message which will be prepended to provide further context.
     *            If it is empty or ends in ":" or ";" or "," or ".", a full
     *            exception message will be appended. If it ends in a space, the
     *            name of the offending object's type will be appended. In any
     *            other case, a ":" with a space and the name of the offending
     *            object's type will be appended.
     * @throws IllegalArgumentException
     *             if the object is not an instance of type
     */
    public static void isInstanceOf(Class<?> type, Object obj, String message) {
        notNull(type, "Type to check against must not be null");
        if (!type.isInstance(obj)) {
            instanceCheckFailed(type, obj, message);
        }
    }

    /**
     * Assert that the provided object is an instance of the provided class.
     *
     * <pre class="code">
     * Assert.instanceOf(Foo.class, foo);
     * </pre>
     *
     * @param type
     *            the type to check against
     * @param obj
     *            the object to check
     * @throws IllegalArgumentException
     *             if the object is not an instance of type
     */
    public static void isInstanceOf(Class<?> type, Object obj) {
        isInstanceOf(type, obj, "");
    }

    /**
     * Assert that {@code superType.isAssignableFrom(subType)} is {@code true}.
     *
     * <pre class="code">
     * Assert.isAssignable(Number.class, myClass, "Number expected");
     * </pre>
     *
     * @param superType
     *            the super type to check against
     * @param subType
     *            the sub type to check
     * @param message
     *            a message which will be prepended to provide further context.
     *            If it is empty or ends in ":" or ";" or "," or ".", a full
     *            exception message will be appended. If it ends in a space, the
     *            name of the offending sub type will be appended. In any other
     *            case, a ":" with a space and the name of the offending sub
     *            type will be appended.
     * @throws IllegalArgumentException
     *             if the classes are not assignable
     */
    public static void isAssignable(Class<?> superType, Class<?> subType, String message) {
        notNull(superType, "Super type to check against must not be null");
        if (subType == null || !superType.isAssignableFrom(subType)) {
            assignableCheckFailed(superType, subType, message);
        }
    }

    /**
     * Assert that {@code superType.isAssignableFrom(subType)} is {@code true}.
     *
     * <pre class="code">
     * Assert.isAssignable(Number.class, myClass);
     * </pre>
     *
     * @param superType
     *            the super type to check
     * @param subType
     *            the sub type to check
     * @throws IllegalArgumentException
     *             if the classes are not assignable
     */
    public static void isAssignable(Class<?> superType, Class<?> subType) {
        isAssignable(superType, subType, "");
    }

    private static void instanceCheckFailed(Class<?> type, Object obj, String msg) {
        String className = (obj != null ? obj.getClass().getName() : "null");
        String result = "";
        boolean defaultMessage = true;
        if (StringUtils.hasLength(msg)) {
            if (endsWithSeparator(msg)) {
                result = msg + " ";
            } else {
                result = messageWithTypeName(msg, className);
                defaultMessage = false;
            }
        }
        if (defaultMessage) {
            result = result + ("Object of class [" + className + "] must be an instance of " + type);
        }
        throw new IllegalArgumentException(result);
    }

    private static void assignableCheckFailed(Class<?> superType, Class<?> subType, String msg) {
        String result = "";
        boolean defaultMessage = true;
        if (StringUtils.hasLength(msg)) {
            if (endsWithSeparator(msg)) {
                result = msg + " ";
            } else {
                result = messageWithTypeName(msg, subType);
                defaultMessage = false;
            }
        }
        if (defaultMessage) {
            result = result + (subType + " is not assignable to " + superType);
        }
        throw new IllegalArgumentException(result);
    }

    private static boolean endsWithSeparator(String msg) {
        return (msg.endsWith(":") || msg.endsWith(";") || msg.endsWith(",") || msg.endsWith("."));
    }

    private static String messageWithTypeName(String msg, Object typeName) {
        return msg + (msg.endsWith(" ") ? "" : ": ") + typeName;
    }

    /**
     * <p>Checks if a String is whitespace, empty ("") or null.</p>
     *
     * <pre>
     * StringUtils.isBlank(null)      = true
     * StringUtils.isBlank("")        = true
     * StringUtils.isBlank(" ")       = true
     * StringUtils.isBlank("bob")     = false
     * StringUtils.isBlank("  bob  ") = false
     * </pre>
     *
     * @param content  the String to check, may be null
     * @return <code>true</code> if the String is null, empty or whitespace
     * @since 2.0
     */
    public static void isBlank(String content, String message) {
        if (org.apache.commons.lang.StringUtils.isBlank(content)) {
            throw new IllegalArgumentException(message);
        }
    }
}
